Nail



Oct. 2o', 1936. J. M. U'PTO'N 2,058,273

- NAIL l Filed Nov. 1o, 1954 -LT AT g5.'

Patented Oct. 20, 1936 UNITED sin-1115s NAIL John M. Upton, Chicago, Ill., assgnor to Filshie Lead HeadNail Co., Inc., Chicago, Ill., a corporation of Illinois Application Nvember .1o. 1934, serial No. 752,403

1 Claim. This invention has vto do with nails, and is concerned more particularly with a nail which seals itself as 'itffisfdriven into final position.

Itis an object of the present invention to economize in the manufacture of nails of this character.

It is another object of the invention to improve the sealing qualities of nails of this character.

It is 'a further object of the invention to produce a nail of this character involving a reduced cost of manufacture and at the same time affording dual inner and outer sealing zones for the head portion of the nail in conjunction with a metallic or other member to be fastened thereby.

In accordance with the general features of this invention, the nail is provided with a preferably convex head which is hermetically sealed by a cap of relatively non-rusting, soft material, such as lead. The cap conforms generally to the head 29 and adjacent shank portion of the nail, but instead'of being made blunt on top and hence sufllciently thick above the head of the nail to insure some of the cap material remaining after the final hammer blow, the cap is substantially thickened only immediately above the central portion of the nail head. This" thickened portion of the cap serves as a means for concentrating the hammer blows so as to prevent the hammer from striking the remainder of the upper part of the cap except at about the last blow, affording an adequate resistance to the hammer blows so as to not unduly thin the metal above the nail head, thus involving a saving in the amount of cap material necessary. 'Ihe portion of the cap surrounding the shank adjacent the head i's recessed upwardly so that the outer periphery of the cap aords a relatively sharp sealing edge, and the shank portion of the cap is fllleted toward the shank and away from the head to provide a second main zone for sealing engagement with the opening in the member to be attached by the nail.

Further important objects and advantages of the invention will appear as the description proceeds.

This invention (in preferred forms) is illustrated in the drawing and hereinafter more fully described.

On the drawing:

Figure 1 is an elevational view of the cap structure of the invention applied to one form of nail.

Figure 2 is an enlarged fragmentary sectional View taken substantially in the plane designated by the line II-II in Figure 1, looking in the direction of the arrows.'

Figure 3 is a view, partly in section and partly in elevation, showing a nail of the invention after the cap has been hammered to enable the nail to fasten material such as corrugated metal roofing to an understructure.

Figure 4 is an elevational viewof a cap applied to another form of nail.

Referring now more particularly to the drawing, the nail, formed with retaining ridges as in Figure 1, at I, or with high pitched threads to render the nail rotatable as it is driven as at 2, is preferably formed with a head 3 which is in the form of a segment of a sphere with its upper surface convex and its under surface at adjacent the shank.

A relatively soft protective cap 4 is cast about the head 3 in such a manner as to substantially entirely enclose the same, and to intimately contact the entire surface of the head and adjacent shank portion. Thus the cap is practically integrally united with the nail. Caps which are cold-pressed over the heads of nails oftentimes are severed from the nail due to an inaccurately struck blow of the hammer. This will not occur with caps which are cast on nails.

Heads heretofore in vvogue have aiforded an excess of metal over substantially the entire upper area of the nail head, in order to insure a covering of the cap material after the last hammer' blow isv struck. The disadvantage of this construction lies in the excessive amount of cap material, thereby unduly increasing the cost of manufacture, particularly to the consumer, who purchases the nails by weight.' In accordance with the present invention, a. substantial quantity of the cap material is saved without sacrificing adequate protection for the nail head after the same is' driven home. The invention affords an additional advantage, sinceit serves to localize or concentrate the impacts due to the hammer blows to the central part of the cap, and consequently in a direction substantially coincident with the axis of the nail.

To these and other ends, the portion of the cap immediately above the nail head is made of a thickness suicient to insure adequate vcoverlng for the head 3 at the cessation of the hammer blows. This thickness is concentrated so as to provide a knob 5, the thickness of the remainder of the dome'portion of the cap 4 being reduced and yet suiiicient to afford proper protection after the nail is driven home. This is made possible by the fact that the blows are concentrated at the knob 5, so that there is relatively little thinning of the remainder of the dome portion of the cap 4..

It has been found that a substantially greater number of nails per pound are afforded than has been true with past capped nail constructions, employing the same size of nail proper.

In addition to making possible a substantial saving in cap material, the present invention, in localizing the hammer blows, aiords a nail structure of improved appearance after being driven home, and enables the nail to be driven home with a minimum of blows, since substantially the full driving power of each blow is effective.

At the underside of the head 3, the cap 4 is formed with an abrupt shoulder 6, extending upwardly to provide a cavity 1, and aiording a relatively sharp peripheral sealing edge 8. The central portion of the cap below the head 3 is formed as a tapered stem 9 projecting below the edge 8 and having a concave contour so as to afford increased wedging cooperation with the wall of the opening I in the corrugated sheet metal roong or the like, a fragment of which is shown in Figure 3 at II. 'I'he stem 9 projects substantially below the edge 8 so that the edge 8 will not interfere substantially with the projecting of the stem 9 into the opening I0. By making the edge 8 relatively sharp, the same will provide a proper sealing cooperation as at I2 with the roong or the like II. This eiect is fortied by the recessing at I of the shoulder 6 to insure the engagement of the edge 8 with the roong or the like I I. 4

Thus when the nail is driven home as shown in Figure 3, the entire edge 8 is bitingly engaged with the surface of the sheetmaterial II entirely surrounding the opening III, and the sharpness of the edge insures uninterrupted contact with said surface so as to afford an effective seal preventing entry of moisture therebetween. The stem portion 9 is likewise forcibly engaged with the wall of the opening I0, affording another complete seal. Thus the nail I is completely protected against moisture.

The projection or teat 5, in localizing the hammer blows, also has the eilect of causing a greater part of each blow to be directed substantially axially, so that with this construction substantially fewer blows are necessary in order to overcome the resistance to the nail in driving the same home. Consequently,rle ss material over the head of the nail cap is required, and when the driving of the nail is completed, a completely adequate amount of cap material remains to adequately protect the head, as shown in Figure 3.

In Figure 3, at 4B, is illustrated the shape of the cap after the nail (or screw) is hammered home, the edge 8 being in biting engagement with the surface of the sheet metal section II of corrugated rooiing or the like; and the zone of the peripheral biting edge being thickened and reenforced.

The nail or screw proper is oi relatively hard material such as iron which is cheap and eective, and the cap is of lead or similar soft material which will serve as adequate sealing means.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

This application is a continuation in part of my copending application, Serial No. 736,201, filed July 20, 1934, entitled Filshie lead head nail.

I claim as my invention:

A composite nail comprising a metal shank having an integrally connected head and a substantially hemi-spherical cap of soft metal enclosing said head and a portion of said shank,

said cap having a lower central portion extendvide cooperable central and peripheral sealing means, respectively, when the nail is driven home into a thing to be fastened, said cap being provided with an upwardly extending and centrally disposed member to receive hammer impact and provide metal owable radially to thicken the peripheral portion of the cap to reenforce the cap in the zone of the peripheral biting edge in the fastening position.

JOHN M. UPTON. 

